Firebox construction



April 20, 1937. s DARLING 2,077,676

FIREBOX CONSTRUCTION Fi led June 14, 1935 2 Sheets-Sheet l April 20,1937. s. M. DARLING FIREBOX CONSTRUCTION Filed June 14,, 1933 2Sheets-Sheet 2 Patented Apr. 20, 1937 NlTED STATES PATENT OFFICE.

FIREBOX CONSTRUCTION Application June 14, 1933, Serial No. 675,683

3 Claims.

The present invention is directed generally to boiler fireboxes, butmore particular-l5 to locomotive fireboxes for securing a completecombustion of the fuel gases therein.

In the conventional locomotive firebox, the combustion space is sorestricted and the time allowed for combustion is so short that it hasbeen impossible, heretofore, to thoroughly mix.

the oxygen, carbon and hydrogen gases so as to secure a satisfactorypercentage of the fuel energy heretofore wasted orto secure a completecombustion of the fuel, inasmuch as this combustion must take placebefore the gases reach the boiler tubes, because there is practi- -callyno further burning after this point in their travel is reached.

Heretofore, in order to lengthen this travel of the gases in alocomotive firebox, it has been the common practice to place in thefirebox a solid bafile, supported by two or more water tubes, to compelall of the fuel gases to travel rearwardly and upwardly around the rearend of the bafile. The objection to this bafile is that it impedes theflow and constricts the'path of the gases and makes necessary the use ofadditional forced draft, which is secured by means of a large, multiplesteam jet blower in the smoke box or stack at the front of the engine.This arrangement is further objectionable in that it involves asubstantial waste of steam and accelerates the travel of the fuel gasesout of the firebox to such an extent that a large portion of them passout the stack unburned, in the form of smoke, resulting in great wasteof fuel and the added nuisance of air pollution.

Another object of the invention is to provide a novel and improved formof locomotive firebox having a novel form of baffle mounted thereinwhich is provided with a plurality of spaced perforations therethrough,so as to permit a substantial portion of the fuel gases to pass throughthese small channels, thus dividing the gases up into many fine streams,and thereby greatly facilitate their mixing together and compel them tocontact a large area of refractory scrubbing surface, thus producing alarge measure of surface combustion.

A still further object of the invention is to provide a novel archconstruction for locomotive firebox which increases the area of path forand reduces the velocity of the fuel gases, thus easing up on the forcerequired to draw them from the firebox into the boiler tubes, resultingin considerable economy of steam heretofore used by the stack blower.

A further object of the invention is to provide a novel steam jet nozzlewhich intimately mixes a hydrocarbon oil, steam under pressure andatmospheric air so as to augment the supply of oxygen and facilitate themixing and combustion to the maximum extent of the gases distilled fromthe coal on the grate.

A still further object of the invention is to provide a novel form ofnozzle located in the opposite sides of and extending through thewaterlegs of the boiler so that they project far enough into the fireboxto be maintained at a relatively high temperature in order to dischargethe mixture therefrom at a high temperature.

A still further object of the invention is to provide a novel form ofnozzle, actuated by high pressure steam carrying a regulated percentageof hydrocarbon oil, which entrains atmospheric air and also a portion ofthe hot gases already in the firebox, mixes them intimately within thenozzle, heats the mixture and projects it at high velocity across thefirebox.

These and other objects are accomplished by providing a construction andan arrangement of the various parts in the manner hereinafter describedand particularly pointed out in the appended claims.

Referring to the drawings:

Fig. l is a fragmentary vertical cross sectional view of a portion of aconventional locomotive engine embodying my improved firebox therein;

Fig. 2 is a cross sectional view taken on the line 22 in Fig. 1;

Fig. 3 is an enlarged detailed View taken on the line 3--3 in Fig. 1;

Fig. 4 is an enlarged vertical cross sectional view taken on the line 44in Fig. 3;

Fig. 5 is an enlarged horizontal cross sectional view showing theconstruction of my improved nozzle;

Fig. 6 is a cross sectional view taken on the line 66 in Fig. 4;

Fig. 7 is a perspective view of my improved nozzle; and

Fig. 8 is a cross sectional view of the three way ejector-valve control,showing the same in closed position.

In one form of my invention, I have shown the same in connection with aconventional form. of locomotive, a fragmentary portion of which isshown in Fig. l of the drawings and generally indicated by the referencecharacter 10. This portion of the locomotive engine comprises an outerwall or housing member H and an inner housing or firebox wall E2, thespace between these walls forming the water circulating or waterleg ofthe locomotive. Extending across the forward end of the firebox is avertical wall l3 to which are connected a plurality of spaced apartboiler tubes, generally indicated by the reference character it. Thesetubes are connected to this wall and extend forwardly in a manner wellunderstood in the art. The rear end of the locomotive firebox isprovided with the usual fire door l4 through which the fuel isdischarged onto the grate generally indicated by the reference characteri5. Extending around the locomotive firebox adjacent the rear sidethereof is a convencharacter 5 8.

One of the essential features of the present invention includes thisnovel arch bafile which is provided with fire clay tile havingperforations therethrough so as to permit a substantial portion of thefuel gases to pass upwardly through a multiplicity of relatively smallchannels, as well as around the rear end of the bafiie, thereby dividingthe gases up into many fine streams, greatly facilitating their mixingtogether and compelling them to contact a large area of refractoryfscrubbing surface, thus affording a large measure of surfacecombustion. With this type of arched perforated baffle, a greater areaof path is afforded, thereby reducing the velocity of the fuel gases,and also reducing the force required to draw them out of the fireboxinto the boiler tubes, resulting in a considerable economy of steam usedby the stack blower. The baflie in this instance, is preferably made ofindividual fire clay blocks, as shown i These refractory tile blocksextend from an inclined portion 28 of the vertical wall M in the forwardend of the firebox upwardly and rearwardly on the tubes l! to a pointsubstantially two-thirds of the distance of the entire longitudinallength of the firebox. Certain of these fire clay tile, particularly theintermediate ones thereof, are provided with spaced apart perforations,as shown at 22. Obviously from the above description, it will be readilyseen that a substantial portion of the gases developed to the rear ofthe bafile will find their way through the perforations E2 in thebaffle, thus dividing up the gases into many fine streams andintermingling them with the volume of gas coming around the rear end ofthe baffle.

In combination with this novel arrangement of bailie construction, Ihave provided a novel arrangement of steam jets which discharge finejets of steam, in combination with a hydrocarbon oil and atmosphericair, through the side walls of the firebox, in a position fore and aftof the b aille, and transversely across it in opposite directions in thefirebox. These nozzles are so constructed that the sharp jets of steam,under full boiler pressure,

draw a quantity of outside air into the firebox and further draw in andrecirculate about an equal quantity of the extremely hot gases alreadyin the firebox and, in the nozzle, mix them intimately with the incomingatmospheric air'and create a violent turbulence in the firebox whichresults in practically complete combustion. This arrangement includes asubstantially U-shaped pipe or conduit extending around the rear andside walls outside the firebox, as shown in Fig. 2 of the drawings, andgenerally indicated by the reference character 25. Connected at spacedapart intervals along the U-shaped pipe 23 are T connections 24, towhich are connected, by' means of reduced pipe connections, as shown at25, nozzles 26. I-hese nozzles extend through spaced apart openings 2?located in the waterlegs on each side of the firebox, as clearly shownin Figs; 2 and 5 of the drawings. The particular construction andfunction of operation of these nozzles form an important feature of thepresent invention. These nozzles are provided with pointed nipples, asshown at 28, having small openings or apertures 29 on the inner endsthereof. Extending from a point below each of the nipples, and formedintegrally therewith, are four oppositely arranged ribs 3%), which inturn, have their inner ends connected to a cylindrical portion 3| whichhas formed on its inner side a Venturi portion, as shown at 32. Byexamination of Fig. 5, it will be seen that these cylindrical or Venturitube portions of the nozzles 26 extend into the firebox a considerabledistance so that a portion of the gases within the firebox may be drawninwardly between the ribs 38 to further heat the hot steam, hydrocarbonoil and atmospheric air mixture and commingling the same with the gaseswithin the firebox. By referring to Fig. 4, the arrows indicate, thedirections of travel of the gases within the firebox passing between theribs 30 and into the discharge nozzle or Venturi of the nozzle. It willbe further observed that atmospheric air is drawn in from outside thefirebox through the openings 27 and passed between the ribs 30 of thenozzle in the manner indicated by the arrows in Fig. 5 of the drawings.The high pressure steam is supplied tothese nozzles and to the U-shapedpipe 23 by means of a connecting pipe 33, which in turn is connected toa supplemental connection or steam pressure box 34 connected to theupper end of the locomotive boiler as clearly shown in Fig. l of thedrawings. Located in the pipe line 33, is a main shut-off valve 35located above the oil supply for completely shutting off the system.Located below this shut-off valve 35' is a three Way ejector-valve,generally indicated by the reference character 37, which is of a specialconstruction and on which a separate application is being filed tospecifically cover the novel features thereof, but for the purpose ofthis application, suffice it to say that the three way ejector-valve 37is manually controlled by lever 38 which actuates the valve member 39.The valve member 39 is provided with a normally vertically extend ingbore 30 which is adapted to register with the connecting ends of thepipe line 33, as clearly shown in Fig. 4 of. the drawings. Mounted inthreaded engagement in a reduced portion of the bore 40 in the valvemember 39, as shown at 4!, is a sleeve 42. The lower end of the bore 40is slightly larger than the outside diameter of the sleeve 42 so as toform an annular channel 43 therearound, adjacent the longitudinal centerof the valve member 39. Located at right angles with respect to the bore4t and extending through one side of the member 39 is a thirdcommunicating passage of relatively smaller diameter, as shown at 44,through which the hydrocarbon oil is drawn and then discharged throughthe annular space 43 surrounding the sleeve 42, so as to evenlydistribute and atomize the incoming oil into the steam in the pipe line33. It will be observed from the above description that when the manuallever38 of the three way ejector-valve 3'! is actuated from the positionshown in Fig. 4, to the dotted line position, shown in Fig. 8, thesource of steam pressure is disconnected from the pipe line 33 and theassociated nozzles and at the same time the oil supply hereinafterdescribed is also disconnected.

In order to accelerate flame propagation through the gases put into aviolent state of agitation by means of the jets of air previouslydescribed, I introduce into the line conveying the steam to the jets inthe nozzles, a few drops per minute of light hydrocarbon oil, such asgasoline, kerosene, petroleum condensate, usually called distillate, orsimilar quickly flashing hydrocarbon oil. This hydrocarbon oil issupplied from a tank 45, fastened by means of brackets 46 to the rearoutside wall of the firebox at a point adjacent the three wayejector-valve 31. The function and operation of this ejector valve is todraw and atomize the oil into the current of steam passing through thepipe 33. The fuel oil in the tank is normally kept under steam pressureby means of a tube connection or pipe generally indicated by thereference character 41, which has one end connected to the main pipeline 33 above the three way ejector-valve 31 and the other end extendinginto the tank to a point adjacent the bottom thereof, as shown at 48.The fuel tank is connected by means of a conduit or pipe 43 to a needlevalve generally indicated by the reference character 50. This needlevalve, briefly, comprises an adjustable needle 5!, for definitelymeasuring or controlling the amount of oil discharged into the steamline. The nozzle of this valve, as shown at 52, extends into a shorthorizontal cylindrical chamber 53 constituting a sight feed mechanism,which is filled with water, as shown at 5:1. Interposed between thischamber 53 and the connection to the three way ejector valve 31, is asupplemental shut-off valve, generally indicated by the referencecharacter 55. From the above description, it will be readily seen thatthe Valve 55 constitutes a manually operable device, by means of whichthe locomotive fireman may close the oil conduit so that the system maybe operated without oil if so desired.

The specific construction of the three way ejector valve, the needlevalve and the cylindrical sight feed is preferably made as a unit and isthe subject of a separate application covering the specific featurestherein.

Summarizing the operation of my improved locomotive fireboxconstruction, let us assume that the steam pressure of the boiler isunder normal full pressure and that the three way valve 31 is open tothe position shown in Fig. 4, and that the needle valve 50 is open so asto permit a few drops of hydrocarbon oil per minute to be introducedinto the steam line 33, from where it is conveyed to the U-shaped pipeconnection 23 into the nozzles 26 located on the opposite sides of theboiler firebox. As previously pointed out, these nozzles are soconstructed that the sharp jets of steam under full boiler pressure,draw a quantity of outside air into the firebox and, further,recirculate about an equal quantity of extremely hot gases already inthe firebox, and in the nozzle, mix them intimately with the incomingatmospheric air. It will also be observed that by reason of the nozzlesprojecting far enough into the firebox, they are sufficiently heated sothat they always maintain a relatively high temperature. At the sametime, it will be observed that as the gases generate in the firebox andare moving rearwardly and upwardly around the rear end of the baflle l8,a substantial portion are passing through the perforations 22 in thebaffie, dividing the gases into many fine streams which together withthe sharp jets directed from the nozzles on the opposite sides of thefirebox intimately mix the various fuel gases and create a violentturbulence therein which results in practically complete combustion bythe time they reach the boiler tubes l8 of the locomotive boiler. Thismethod of creating a violent turbulence and intermixing of the fuelgases within the firebox and supplying additional oxygen and atmosphericair, practically insures a complete combustion of all of the gases andreduces the amount of waste of fuel to a minimum.

While in the above specification I have described one embodiment whichmy invention may assume in practice, it will of course, be understoodthat modification may be made without departing from the spirit andscope of the invention as expressed in the following claims.

What I claim is my invention and desire to secure by Letters Patent is:

1. The combination with a locomotive boiler including a firebox adaptedto burn solid fuel, of a baffle mounted in said firebox having aplurality of perforations therein for permitting a substantial portionof the gases from burning solid fuel to pass therethrough, a pluralityof nozzles extending through the walls of said firebox projecting asubstantial distance therein, certain of said nozzles located forwardlyand certain other of said nozzles located rearwardly of said baffle, asteam pipe line connecting said boiler with said nozzles for furnishingsteam under pressure thereto, a manually controlled ejector forintroducing a predetermined amount of hydro-carbon oil into said steampipe line, and means adjacent each of said nozzles for introducingatmospheric air around said nozzles and mixing it with the steam andatomized hydro-carbon oil and discharging the mixture through saidnozzles so as to set up a violent turbulence of the gases on theopposite sides of said baffle.

2. The combination with a locomotive boiler including a firebox adaptedto burn solid fuel, of an upwardly and rearwardly arched baffle mountedin said firebox having a plurality of apertures therein for permitting asubstantial portion of the gases from burning solid fuel to passtherethrough, a plurality of spaced apart nozzles extending through theside walls of said firebox and extending thereinto, certain of saidnozzles located above said baffle and certain other of said nozzleslocated below said baffle, a steam pipe line for furnishing steam underpressure from the boiler to said nozzles, a manually controlled ejectorfor delivering a regulated amount of hydro-carbon oil to said steam pipeline, means for introducing atmospheric air to the firebox around saidnozzles, and means for drawing a certain portion of the gases withinsaid firebox into said nozzles and mixing said last named gases withsaid steam, hydro-carbon oil and atmospheric air and discharging themixture so as to set up a violent turbulence within said firebox.

3. The combination with a locomotive boiler including a firebox adaptedto burn solid fuel, of a bafile mounted in said firebox having aplurality of perforations therein for permitting a substantial portionof the gases from burning solid fuel to pass therethroug h, a pluralityof nozzles extending through the walls of said firebox and projecting asubstantial distance therein, said nozzles located forwardly andrearwardly of said bafile, a steam pipe line connecting said boiler withsaid nozzles for furnishing steam under pressure thereto, a manuallycontrolled three-way ejector valve for introducing a predeterminedamount of hydro-carbon oil into said steam pipe line, and means forintroducing atmospheric air around said nozzles and mixing it With thesteam and. hydro-carbon oil discharged from said nozzles and dischargingthe mixture through said nozzles so as to set up a violent turbulence ofthe gases on the opposite sides of 10 said bafiie.

SAMUEL M. DARLING.

